Eric Holder, US General Attorney said: "Beginning in the summer in 2009 we allege that the executives at the highest level in the companies included in today's lawsuits, concerning that e-book sellers had reduced prices, worked together to eliminate competition among stores selling e-books, ultimately increasing prices for consumers."

Settlement has been reached with three of the accused, while the remaining three, including the $600 billion company Apple, are yet to have their case resolved.